Further mechanistic studies showed that the AnSC-Exos-specific miRNAs, let-7b and let-7a, appear to have played a critical role in inhibiting CCL7 expression of the fibroblasts which, in turn, reduced recruitment of monocyte-derived macrophages on site and macrophage polarization to M2, contributing to the alleviation of PF. Here, CCL7 is linked to pemphigus foliaceus.